Dental alloy



Patented June 1 7, 1941 UNITED STATES PATENT OFFICE DENTAL ALLOY Maude tBraid, Hartsdale, N. Y.

7N0 Drawing. Application July 2, 1940, Serial No. 343,559

2 Claims.

This invention relates to an alloy of the class containing nickel and chromium and more particularly relates to an alloy suitable for dental purposes, 1. e. for dentures, plates, pins, etc. as well as other purposes in which high resistance to corrosive attack is an essential.

. An object of my invention is to provide an.

improved alloy particularly suitable for dental purposes.

A further object of the invention is to provide an improved alloy possessing a tensile strength and hardness greater than thatof the ordinarynickel-chrome alloys and one which while ductile has its yield point sufliciently high for use as a are the usual and natural elements for denture use. The molybdenum acts to lower the melting point and increase the fluidity while the tungsten is employed for its toughening and hardening qualities. I regard the inclusion of zirconium as a novel and essential ingredient in this type of alloy. It has a two-fold advantage firstly as a hardener but more importantly as a powerful deoiiidizer. v

The ingredients of my new alloy may be employed in a wide range of percentages, for

example- Per cent by weight Chr 10 -49 Nickel 10 -40 Coba 20 -48 Molybdenum 3 Tungsten 3 -i2 Zircon m .25- 3 but I have found that for use as a denture the following composition is to be preferred viz:

Per cent by weight Chromium 30 "Nickel 15 Cobalt Molybdenum 5 Tungsten 5 Zirr-nnium .25

In the production of my new alloy I prefer to employ the relatively recently known process of alloying known as powder metallurgy which briefly stated consists in fine grinding the metals,

e. g. to 250 mesh, intimately mixing the same and placing the mixture in a die in which it is subjected to high pressure (of the order of 50 tons). A hard solid mass results which is then inserted into a furnace and subjected to sintering heat. It will be noted that at no time are the metalsmelted. V

This process is particularly advantageous in the production of my new alloy as' by it I am enabled to control very closely the proportions of each ingredient in the final product as losses particularly of molybdenum and zirconium due to volatilization are avoided or greatly minimized. It will be understood however that I do not conflne myself to using this processor production of the alloy as-any usual or known process may equally well be employed.

V What I claim is: I

1. An alloy consisting of 10-49% chromium,

. -48% cobalt, 345% molybdenum, 10-40% nickel, 3-12% tungsten and 0.254% zirconium; 2. An alloy consisting of about chromium,

about 45% cobalt, about 15% nickel, about 5% molybdenum, about 5% tungsten and about 0.25% zirconium. j

MAUDE BRAID. 

